Application of MRPID controller on liquid level system: A performance study

Comparative study of the performance of Wavelet based Multi Resolution PID (MRPID) controller over conventional PID controller for a Liquid level system is presented in this paper. In the proposed wavelet based PID controller, the discrete wavelet transform (DWT) is used to decompose the error signal available from the set point signal and measured signal into different frequency components at various levels. Then the calculated DWT coefficients are multiplied with their respective gains to generate an overall control signal. Both the controllers are simulated in LabVIEW software. After implementation of software model successfully, plant is realized in hardware with controller simulated in PC. The performances of the wavelet-based MRPID controller are found to be superior to that of the conventional PID controller even in the presence of the white noise.